Film fans everywhere are mourning the loss of screen icon Marlon Brando, who died Thursday in Los Angeles at the age of 80. His six-decade career that includes performances that continue to inspire new generations of actors.

You don't understand. I could've had class. I could've been a contender. I could've been somebody instead of a bum, which is what I am. Let's face it.

From his anguished ex-boxer in the 1954 social drama On The Waterfront to his definitive Mafia crime boss Don Vito Corleone in 1972's The Godfather.

I'm going to make him an offer he can't refuse.

Marlon Brando could achieve a greatness that deeply touched audiences and his co-stars, like James Caan who played Sonny Corleone in director Francis Ford Coppola's The Godfather.

"I don't care who tells you differently, they're lying: anybody my age or a little younger or a little older - if they tell you that he wasn't their biggest influence, they're lying," Caan says. "He was the biggest influence. It was like meeting royalty. He was great. He had an ability to be available to anything at any time. He was one of the great instinctive guys, but he worked a lot harder than he liked to let on. He worked pretty hard."

Born in Omaha, Nebraska in 1924, Marlon Brando grew up in the Midwest, but moved to New York at the age of 19 and began studying the then-new "method" style of realistic acting. His riveting Broadway theater performances caught the attention of Hollywood and in 1951 he made his mark shouting "Stella!" as Stanley Kowalski in director Elia Kazan's production of A Streetcar Named Desire. Karl Malden, who co-starred in Streetcar and played opposite Brando in three films as well as two stage productions, says "he changed the style of acting in America."

Robert Osborne, veteran industry observer and columnist for The Hollywood Reporter trade paper, says that impact was apparent from the beginning.

"When Marlon Brando first came on the screen . . . actually, his first movie was in 1950 called The Men, but the big impact was the following year when he did A Streetcar Named Desire ... nobody had seen an actor like that before because not only did he look like a movie star, but he had a naturalism to him and a dynamic personality that was unlike anything anybody had ever seen before. It was kind of the best of the Actors Studio and realistic acting, not the kind of theatricality - the John Barrymore style of acting - that had been dominant in the business for years.

It was a change that took some getting used to, however. Austrian-born actor Maximillian Schell first worked with Brando in the 1958 war drama The Young Lions.

"I didn't like Marlon Brando in films. [He mumbled] 'Baby, I love you ...' and all this. I thought 'why?' Then I met him and we couldn't speak. I couldn't speak one word of English and he couldn't speak German," he said. "So he tried to speak French and we were two hours in his dressing room near Paris and I thought he was a great personality. That's what counted. He was just different: wonderful face and a sense for justice and also for the good."

Karl Malden describes that as "an empathy for the underdog" which extended beyond his acting. A champion for social justice causes, Brando refused to accept the Best Actor Oscar for The Godfather in 1973, instead sending Indian activist Sasheen Littlefeather to read a powerful statement about Hollywood's treatment of Native Americans. Partly because of actions like that, in part due to his intense acting style and also because of his reclusive lifestyle Brando also developed a reputation for being troublesome on the set. Godfather co-star Caan blames the filmmakers.

"I think the directors at that time, other than Francis [Ford Coppola], were all trying to control him, so there was this whole mystique about him being difficult," he said. "He never wanted to be controlled. He just wanted to be talked to."

Critics agree that not all of Brando's choices worked out. For instance, his Marc Antony in the 1953 version of Julius Caesar or the movie of the musical Guys and Dolls. However, columnist Robert Osborne says it is all part of a remarkable career.

"I don't regret at all the Brando films that we have - even the bad ones like Teahouse of the August Moon, which isn't so great, and The Appaloosa - there are a lot of turkeys in there; but I regret all those films he didn't make," he says. "He really didn't work all that much and he did seem, to me, to squander a talent that was extraordinary. To not do better work or not have a larger body of work is somewhat sad."

Still, Osborne acknowledges, Brando has a prominent place in Hollywood history.

"Three of the films that he made are such iconic films to us now: A Streetcar Named Desire and On The Waterfront which came three years later and then The Godfather, which came in 1972," he says. "That covers a wide spectrum of acting; but I think those three films alone with keep Marlon Brando a heavy influence because what he did in Streetcar and Waterfront and Godfather is absolutely timeless and those performances are not dated at all."